package callable;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;


//基于 Callable 实现 1+2+3+...+1000
public class Main {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        Callable<Integer> callable = new Callable<Integer>() {
            @Override
            public Integer call() throws Exception {
                int sum = 0;
                for (int i = 1; i <= 1000; i++) {
                    sum+=i;
                }
                return sum;
            }
        };

        // callable的返回值是Integer，所以Future泛型参数是Integer
        FutureTask<Integer> futureTask = new FutureTask<>(callable);
        Thread t1 = new Thread(futureTask);
        t1.start();

        Integer result = futureTask.get();
        System.out.println(result);

    }
}
